Alfred holmgren



UNITED STATES. PATENT OFFICE.

JOIIN DRAPER ANDY}? ALFRED HOLMGREN, or BROOKLYN, New YORK,

ASSIGNORS OF ONE-HALF TO HENRY .RITTER MOUNT AND JOHN BARNES, BOTH OF SAME PLACE.

lNCRUSTATION-PREl/ENTIYE.

SPECIFICATION forming part of Letters Patent No. 43,882, dated June 9, 1891. Application filed April 26, 1890. Serial ll'o. 349,658- ](No specimens To all whom it may concern: v and the surfaceof the ironor steel, and by 50 Beitknown thatwe, J HN'DRAPER,chemist, the action of the heat upon the mercury or anClALFRED .I IOLMGREN, consulting engineer, upon the*water which may enter the crevices both of the city of Brooklyn, county of Kings, the scales are detached from the metal and and State of New York, have invented an Immay readily be removed from the boiler.

proved Method or Process for RemovaL-and The best results have been obtained in our Prevention of Scales or Incrustation in Steamexperiments by the use of about .ninety per Boilers; and we'do hereby declare that the cent. of mercury and .ten'gper cent; of hifollowing is a full, clear, and exact descripchloride of mercury whelrthfl boiler is supro tion of the invention, which will enable others plied with salt-water When.v fresh Water is skilled in the art to which it appertains to supplied to the boiler, the proportions to promake and use the same. duce the best elfect have been attained by the I The chief object of said invention is to preuse of eighty-seven per cent. of mercur ten vent theformation of scales and incrustations per cent. of bichloride of mercury, and three [5 in steam-boilers and to remove scales already per cent. of metallic sodium, The proporformedin boilers and boiler-tubes; and it contions requisite to produce a uniform eifect 6 sists, essentially, in placing mercury in conwill vary somewhat with the character of the nection with bichloride of mercury and meboiler and the qualities oT the water. 2 tallic sodium in the b0iler,which, subjected. to In carrying our invention into practice we 2o heatandsteam-pressure, formsasmooth glassy first introduce the bichloride of mercury into.

coating or surface. The formation of said the boiler, and after the same has been dis- 7o coating or surface is hastened by the addition solved in the water we introduce the mercury of thebichloride of mercury, and when boilers or a mixture of mercury and metallicsodium, are'supplied with fresh water we find the ad \Ve prefer to mix the mercury and metallic 2 dition of metallic sodium an advantage, and sodium before application; but these subthat the addition of bichlo'ride of mercury stances may be applied separately without and metallic sodium renders the process more materially impairing the beneficial results; speedy and perfect. The metallic sodium is of flhe object of first introducing thebichloride no appreciable advantage when the boiler is of mercury, which is easily dissolved in water 30 supplied with salt-water, and may be then andhasastrongafiinityformetal,is to quicken omitted. The coating or glassy surface is the process and improve the character of the formed by the action of these substances on coating or glassy surface. The metallic sothe iron or steel with which they come in con dium assists the process and acts as an amaltact.- Our experiments indicate that chemigamator.

3 5 cal action takes place in the boiler, forminga \Ve have ascertained by a series of experi-- union of these substances with the metal; but ments that, two pounds of the material for 85 the success of the method seems dependent every one hundred horsespower will keep a upon the effect of heat and steam-pressure in' steam-boiler suppiied with fresh water clean the boiler, whatever may be the natureof the for six months. In some conditions it may 0 action. The exact degree of heat in the boiler be desirable to renew the applications at to produce the best cficct has not been deshorter intervals. The engineer by examine; go, termincd; but it should be sufficient to protion of the boiler will be able to determine duce steam-pressure. The mercury, having the necessity of introducing more of the maan alfinityforiron and steel, formsunder these terial. The said substances have no injuri- 45 conditions a permanent coatiug or smooth ous effect upon the metal with which they T glassy surface which resists rust and prevents come in contact and are open to none of the the formation of scales or incrustati'ons. The objections urgcdagainst the meanshcretofore.

minute particles of mercury penetrate beadopted'for alike purpose. tween thcscalcs, when thcsehavebeen formed, The vegetable substances heretofore supheat.

The advantages of havingboilers kept clean are well known, among which is economy of fuel, which we have proved is efiectcd by the theuse of our invention.

Having fully described our invention, what we claim, and'desire to secure by Letters Patent, is

The method of internally coating a steamboiier to prevent incrustation, consisting in subjecting the surface of such boiler to the action of water, bichloride of mercury, and :5

mercury and sodium under heat and pressure, as set forth.

" JOHN DRA'PER.

ALFRED IIOLMGREN Witnesses:

ISAAC O. HORTON, J u, HENRY- R. SUYDAM. 

